10 ALASKAN GLACIER STUDIES The tidal glaciers that enter Lituya Bay have advanced 2% to 8 miles between 1786, when mapped by LaPerouse, and 1894 when mapped by the Canadian Boundary Survey.1 Dall2 thinks at least a mile of this advance was between 1874 and 1894. One of these glaciers advanced another half mile between 1894 and 1906.8 Farther west is the Grand Plateau Glacier, formerly thought to be nearly as large as the Malaspina and Bering Glaciers. It is quite unexplored but is plainly visible from the steamer. It was named by LaPerouse and described by Vancouver4 and by Dall.B What was erroneously mapped by the Boundary Survey in 1895 as one large piedmont glacier was clearly seen by the Junior author in 1918 to be at least two separate ice masses. Glaciers of the Lower Alsek River. These ice tongues include at least one through glacier heading eastward on the Glacier Bay divide and a number of through glaciers heading westward on the divide with the glaciers of Russell Fiord. They were first seen by Glave who came down the Alsek River in 1890.B He described five great glaciers, of which the lowermost, Alsek Glacier, is the only one bearing a name. One of these is the northern terminus of the through glacier called Grand Pacific Glacier in Glacier Bay. At least one other is a through glacier whose western termini are Nunatak and Hidden Glaciers of Russell Fiord and Yakutat Glacier, east of Yakutat Bay. The Alsek Glacier and part of the glacier system west of the river were mapped by the Boundary Survey in 1895.7 In 1906 Blackwelder and Maddren visited, mapped, and briefly described the Alsek Glacier as well as the Yakutat Glacier and smaller ice tongues of the mountain front between Alsek River and Russell Fiord,8 several of which had been roughly mapped by a United States Fish Commission party in 1901.B In 1906 and 1908 the Boundary Commission parties ascended the Alsek, making more detailed maps and observations of the ice tongues surveyed by Glave and the Canadian Boundary Survey party of 1895. They found10 the northern terminus of Grand Pacific through glacier retreating while the glacier at the upper canyon was advancing and crushing alder bushes. The glacier next above Alsek Glacier, a terminus of the Nunatak-Hidden-Yakutat through glacier system, was %\ miles back from the river and thoroughly stagnant. Alsek Glacier was more active in 1908 than in 1906. The ice-flooded region between Alsek River and Russell Fiord is a typical glaciated region, with all the valleys filled with ice and many detached ridges and peaks rising above the glacier and snowfield.11 It is a distance of 39 to 42 miles by the through glacier sys- • Hotz, Otto, Geog. Journ., Vol. XIV, 1899, pp. 624-526. »Dall, W. H., in H. P. Reid's Variations of Glaciers, Journ. Geol, Vol. VII, 1899, p. 226. • Wright, P. E. and C. W., Journ. Geol., Vol. XVI, 1908, p, 53. «Vancouver, Capt. George, Voyage of Discovery, Vol. V, London, 1801, pp. S58-S59. «Dall, W. H., Journ. Amer. Geog. Soc., Vol. XXV3H, 1896, p. 8. •Glave, E. J., Leslie's Illustrated Newspaper, Vol. 71, 1891; Century Magazine, Vol. XXII,1892, p. 880. i Atlas of Award, Alaskan Boundary Tribunal, Sheet 20; PI. VII, Professional Paper 64, U. S. Geol. Survey, 1909. • Blackwelder, Eliot, Journr Geol., Vol. XV, 1907, pp. 415-433. • PI. XLin, Bull. 21, U. S. Pish Commission, 1902. " Morse, Premont, and Netland, L., Journ. Geol., Vol. XVII, 1909, pp. 669-370; see also photographs, Nat. Geog. Mag., Vol. XX, 1909, pp. 697. 598, 605. ii Atlas of Award, Alaskan Boundary Tribunal, Sheets 20 and 21.